wackazong

Hi, I have a project for a MBHP that needs to store some data (about 4kB) in the memory of the PIC. I am using the PIC18F4685, therefore I should have enought memory. What is the best way to organise this memory? I know that you cannot use arrays that are bigger than 256 bytes, therefore I am thinking of using multiple arrays of 256 bytes (16 for 4kB). Is there a more convenient way? May using short assembler parts which access the memory? Any ideas? I am storing the I2C addresses of 48 LED drivers, the corresponding LED addresses on these drivers, and the LED state (256-step indiviual PWM) for each LED (in total 3*256 LEDs). Storing all this on the PIC makes the interface to the computer so much easier and faster. Thanks, ALEXander.

To explain my situation, why redesigning the pcb does not make much sense: I have a pcb which supports 16 buttons and 16 rgb leds. The 16 buttons are connected to a DIN module with two shift registers. This pcb is intended to be chained together to form a button matrix of almost any (well, up to 256 buttons it should be) size. If I use the normal DIN concept, I just need three wires running from board to board, which is extremely convenient. This would not be possible with a matrix solution. So, what do you think I should do in this situation? Thanks, ALEXander.

OK, I got it working. I generated a simple application sceleton which uses a c and an asm part, and links them both together. so far, only one byte is supported for parameters or return values. anybody care? I will extend it soon. Best, ALEXander. BTW: is SET_BSR "Set the Bank Select Register"? Took me a while to figure that one out. But now it works.

Well, wouldn't it just be increasing the counter of the serial shift register inputs to 256? Or am I completely wrong here? ALEXander.

Hi, I am in the process of making (and soon hopefully documenting...) a button matrix of 256 buttons, each one with its own RGB LED, which can be controlled via MIDI. At the moment I am wondering whether it would be possible and feasible to route 256 digital inputs via DIN-Modules into one core. I can control 256 LEDs with one core (via I2C, working beautifully), the maximum number of 128 digital inputs would be the only reason that I need another core and the MBLink feature. I am shure this would work, but it would mean more systems, more interfaces, and more hardware. I cannot easily use a button matrix because of the modular setup of my pcbs, the matrix is more complicated regarding routing, and my routing is already very complicated (I am already forced to use a 4-layer pcb). So, if it is possible and can be done with acceptable latency (>100Hz) then I would like to reprogram the corresponding MIOS routine to support 256 buttons. Any tips for me? Thanks! ALEXander.

Hi, in all MIDI Monitors, also in MIOS Studio, there is a "MIDI timestamp" or "MIDI Time Stamp". On the web I could not find what the format of that timestamp is. Can somebody explain that to me? How do I see whether the MIDI Event that I receive contains a timestamp? It should come before the status byte, but how is its format defined? I looked at a lot of "MIDI spec explained" sites, but I did not find an answer anywhere. Thanks, ALEXander.

Thanks, I only looked in the base package and did not find an app where I could really understand what was going on.

Hi, I managed to get my own C program running on MIOS, based on the sdcc_skeleton files. Now I want to integrate TKs random function into my program: ;; -------------------------------------------------------------------------- ;; This function generates a new random number ;; OUT: new random number in SEQ_RANDOM_SEED_[LH] ;; -------------------------------------------------------------------------- SEQ_CORE_GenRandomNumber SET_BSR SEQ_BASE movf SEQ_RANDOM_SEED_L, W, BANKED mulwf SEQ_RANDOM_SEED_H, BANKED movf TMR0L, W addwf PRODL, W movwf SEQ_RANDOM_SEED_L, BANKED movlw 0x69 addwfc PRODH, W movwf SEQ_RANDOM_SEED_H, BANKED return How do I define this as an assembler function that I can reference in C? I could not find a mixed C/Assembler example project. Many thanks, ALEXander.

Hi! I cannot find the C skeleton anymore? Is it part of the base package now? Sorry, but I am a first timer, and last time I installed the XCode stuff I actually did not do any coding. And: How do I adjust the C Skeleton to work on a PIC18F4685? That ist the one I am using. Thanks! ALEXander.

Hi! Is this still ongoing? If yes, please put me on the list for a x0xb0x. Best, ALEXander.

Hi! I just successfully made a core, with one little issue: On the PCB from Mike there was a tiny copper lead between GND and VDD, just close to the pins J2. Not really an issue, but it took me four pieces of "Krokodilklemmen" smoldering away (I have a 100W 5V supply) to find that out. Should not be there. But the lead could be removed very easily, now everything works fine. Just for you others out there, wondering why your core PCB does not work. Best, ALEXander.

Ok, so to narrow down my question: If I have a design which requires the standard 10k Pull-Up resistors that are used in the standard DIN design, is there a shift register with integrated pull-up registors that I could use? Best, ALEXander.

Well, I did everything how Audiocommander told us to do it and.... it works! Thanks!

Well, on second thoughts I think I will go with the "normal" solution nevertheless, because i can modularize it better. With the normal input solution, i can put one or two 74hc165 on one pcb, together with buttons and leds, and interconnect them with just a couple of wires. for the matrix, I would need more wires. Best, ALEXander.

Hi Cimo! Thanks for helping a newbie... Yes, now I have it. I think I got a bit confused... sorry. I found the "How to use MIDIBox Link with the COM-port" drawing now. I think I will go with that solution, and maybe in the future try to connect the whole think to a FT232 to go via USB. Thanks! ALEXander.

One again: The AN2131SC does not seem to be available anymore, I checked with Reichelt, Mouser, DigiKey and Arrow. So the FT232 seems like a good option to me, because it is well supported with the Virttual Com Port driver. I do not want to develop my own USB driver for OSX, I am not that used to programming for Mac. But, the question still remains: How do I combine the two interfaces into one? One MIDI in from one core, and one MIDI out from another core. Or would it be better to dedicate one core to the MIDI in/out communication and to talk to the other cores via MBnet? But where can I find examples for MBnet? Any help is greatly appreciated. Thanks! ALEXander.

Allow me to reply to myself: Seems like the MBHP USB is a good idea, since I can connect two cores directly. But here I cannot simulate a serial interface, or can I? How does it work on the Mac side: Do I have to load a driver? Has anybody used this module under MAC OS X? Also: The microcontroller from Cypress seems to be obsolete, and I could not find the development software anymore. There is a new chip (EZ-USB FX1), but there does not seem to be free software for it. Does anybody know of a USB controller chip with two USART's which could be used for the described task? ALEXander.

Hello again, one more thing came to my mind today: For my project (a module for 128 buttons and a RGB LED for each button, no velocity) I would like to send the MIDI Data via a MIDIBox-to-COM interface to my computer (possibly over USB, but that only needs a converter using a FT232). I would like to access the serial port via my own software on my Mac. I will chain some Cores together in my Project. Now it came to my mind, that in that situation, I have two MIDI ports at two cores, which I need to combine: The MIDI port at the first core, and the one at the last core. Is it possible to combine that to a single COM-port? I see the following solutions: - a MIDImerger (probably quite slow) - a MBHP-USB interface (has somebody tried that on OS X? Does it need special drivers on the Mac side?) - aren't there chips which can combine two different serial ports? The thing is that one will only be used for sending data, the other will only be used for receiving data Another solution could be to use MBnet and to use one Core as the main interface to the Mac. I like that solution, because I think it would be fast and is also very extendable. Unfortunately I did not find much on the MBnet on the ucapps pages, there is no examples. Does it work? I did not find any functions in MIOS relating to it. I attached a picture to explain what I wrote. Thanks, ALEXander.

Hello, I found the C Example for a Button Matrix concept for MIOS. I have the same task, I need to scan at least 128 buttons (256 max) quickly with one core. Now I started wondering: What are the advantages/disadvantages of that button matrix in comparison to using standard DINs for 128 Buttons (means 4 fully equipped DIN modules) regarding - speed/performance - accuracy (missed button presses) - memory usage (on the same PIC, I want to do some I2C communication as well, if possible) I looked around in the forums and in the wiki, but did not find much... There is the 16x16 matrix that QBAS developed, but I did not find a comparison to the old system of using chained DINs. Thanks, ALEXander. Thanks! ALEXander.

Now it all makes sense to me :) Best, ALEXander.

But: Now I have the problem that I would like to drive two I2C Buses, for the simple reason that I want to be able to adress my LED-matrix' rows and columns with subadresses. Because I need a subadress for each row, column and color, there are a lot of adresses pretty fast. Is it possible to use two I2C buses from one core, or should I use two cores? What do you think? Thanks, ALEXander.

Ok, sounds fair enough. Best, ALEXander.

Hi Thorsten, uh, I have no definite idea yet, I was just thinking about different ways to connect different cores.... And maybe the control of my PCA6935 would be safer with the internal I2C. But you are right, the normal linking concepts should be enough. ALEXander.

My fastest so far was TI: Samples send from the US in two days, via international courier, at no cost at all for me. Pretty impressive.

I am thinking about backlit buttons as well at the moment. Nikkai has some ok pushbuttons, but they are still rather costly (but much cheaper than the rest). You will have to write to them to find the local distributor.Mine is http://www.invertag.ch/, they sell me the KB and YB series for about USD 5 per button, if you order 200 pieces. But most probably I will make my own: Take a 25mm aluminium square hollow profile, stick some 6mm opaque acryl into it, put an smd led and a small smd printbutton below, voila, there is your illuminated switch. Another idea is here: http://www.anyma.ch/2005/research/make-your-own-illuminated-buttons/ Best, ALEXander.